In order to make the coal slurry rapid precipitation in a concentrated tank, ensure qualified washing water and filter slime production, the production efficiency and economic operation, treatment must choose suitable flocculant to strengthen coal slurry. Through the production practice in recent years, polyacrylamide on slime water treatment effect is good, can accelerate the settlement of coal slurry, and contribute to the production of filter press.

Polyacrylamide flocculation mechanism referred to as PAM, is a kind of linear polymers, non-toxic, non corrosive, Yi Rong in water, its water solution and coal slurry mixing, adsorption of polyacrylamide on the molecular chain of active groups in coal slurry and fine particle surface, the connecting role between the particles, the fine particles into larger floc to speed up the rate of sedimentation, slime.

Polyacrylamide aqueous solution preparation of Xinji Coal Preparation Plant by polyacrylamide gel as the preparation of raw materials, the solid content is 3.75%, the molecular weight is about 8000000. According to the prepared polyacrylamide solution concentration of 1 per thousand calculates the required water quantity and amount of colloid to the mixing barrel, into the water, starting a blender, slowly into the polyacrylamide gel, stir to dissolve; colloidal, stirring barrel liquid into a colorless transparent liquid, and the liquid without undissolved condensation or block, stop stirring, complete the preparation of polyacrylamide solution. The preparation process should be taken to avoid excessive agitation to cause degradation of polyacrylamide molecules.

The addition of polyacrylamide aqueous solution of polyacrylamide aqueous solution is the key step in slime water treatment, by adding appropriate methods, will help to improve the effect of flocculation. The factory after years of production practice and observation, gradually improved, forming a dosing device; we take the following ways: add production, open the discharge valve to a certain degree, start the chemical pump, the polyacrylamide solution was injected into the slime water. In the coal slurry dosing point with local Francis, contribute to the coal slurry particles in the formation of flocs. The factory is set in the dosing point in the water distribution. In order to ensure uniform and stable dosing time, the slime precipitation, the production process used in at least 2 chemical mixing barrel, on a polyacrylamide solution before the infusion, another tube solution has been prepared to complete, in order to maintain the continuity of reagent addition. Dosing is not stable, it can easily result in overflow concentration exceed the standard. In medicine, should observe the concentrated pool of slime water sedimentation, overflow concentration between 30 ~ 40g L.PAM dosage for the treatment of coal slurry, must add the appropriate amount in order to effectively play the role of flocculation. According to the selected process of slime water treatment and coal slurry properties determined through test. The amount of at least lead to coal deposition slow, concentrated overflow easily exceed the standard, can not guarantee the required water circulation index, so that the coal product indicators are difficult to control. Too much, although accelerated the sedimentation rate of the slime, but easy to cause the concentration of underflow concentration is too high; general concentration underflow concentration requirements in 500g L, can meet the press production; excessive amount of concentrated underflow concentration sometimes high above 700g L, and polyacrylamide content in the underflow increased, so the bottom transport and filter production adversely, the filter is not easy to fall off when unloading the briquette briquette, increase the labor intensity of operators, reduces the work efficiency; at the same time also caused chemical waste, increase the cost of production. Therefore, proper use of polyacrylamide, can not only improve the flocculation effect, effective treatment of coal slurry, and to ensure also play an important role in reducing cost, improving efficiency, coal product index.